U.S. patent number 6,761,503 [Application Number 10/131,752] was granted by the patent office on 2004-07-13 for splined member for use in a slip joint and method of manufacturing the same.
This patent grant is currently assigned to Torque-Traction Technologies, Inc.. Invention is credited to Douglas E. Breese.
United States Patent |
6,761,503 |
Breese |
July 13, 2004 |
Splined member for use in a slip joint and method of manufacturing
the same
Abstract
An improved female splined member includes a female tubular
member having an inner surface provided with a plurality of
longitudinally extending grooves that are sized and spaced in
accordance with a desired number and position of splines to be
formed. A plurality of elongate rods is disposed in respective
longitudinally extending grooves formed in the inner surface of the
female tubular member. A quantity of positioning material is
provided within spaces provided between the elongate rods and the
longitudinally extending grooves. The positioning material is
hardened to support the elongate rods in the longitudinally
extending grooves to define a plurality of inwardly extending
splines in the female splined member. An improved method for
manufacturing a female splined member includes the initial step of
providing a female tubular member having an inner surface provided
with a plurality of circumferentially spaced, longitudinally
extending grooves. Next, an elongate rod is provided in each of the
longitudinally extending grooves in the female tubular member.
Then, a quantity of positioning material is provided into spaces
provided between the elongate rods and the longitudinally extending
grooves in the female tubular member. Thereafter, the positioning
material is allowed to harden.
Inventors: |
Breese; Douglas E. (Walbridge,
OH) |
Assignee: |
Torque-Traction Technologies,
Inc. (Holland, OH)
|
Family
ID: |
29215597 |
Appl.
No.: |
10/131,752 |
Filed: |
April 24, 2002 |
Current U.S.
Class: |
403/359.5;
384/49; 464/167 |
Current CPC
Class: |
F16C
3/035 (20130101); F16D 3/065 (20130101); Y10T
403/7033 (20150115); Y10T 403/7031 (20150115) |
Current International
Class: |
F16D
3/02 (20060101); F16C 3/02 (20060101); F16C
3/035 (20060101); F16D 3/06 (20060101); B25G
003/28 () |
Field of
Search: |
;403/359.1,359.3,359.5,359.6,359.2,359.4,355,358 ;464/167,168
;384/49,51 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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197 35 443 |
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Feb 1999 |
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DE |
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198 17 290 |
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Oct 1999 |
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DE |
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1065397 |
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Jan 2001 |
|
EP |
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2000160101 |
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May 2000 |
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JP |
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WO 99/25983 |
|
May 1999 |
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WO |
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Primary Examiner: Browne; Lynne H.
Assistant Examiner: Schiffman; Jori
Attorney, Agent or Firm: MacMillan, Sobanski & Todd,
LLC
Claims
What is claimed is:
1. A slip joint comprising: a first member including a surface
having a first plurality of grooves formed therein, a rod disposed
in each of said first plurality of grooves, and a quantity of
material extending between said first member and each of said rods
for retaining said rods within said first plurality of grooves to
define a plurality of splines on said first member that extend
beyond said surface; a second member including a surface having a
second plurality of grooves formed therein; and a plurality of
balls disposed in each of said second plurality of grooves, said
plurality of balls cooperating with said rods on said first member
to provide a rotatable driving connection between said first and
second members, while permitting relative axial movement
therebetween.
2. The slip joint defined in claim 1 wherein each of said first
plurality of grooves extends longitudinally along said first
member.
3. The slip joint defined in claim 2 said rods are elongated and
are disposed in said first plurality of longitudinally extending
grooves.
4. The slip joint defined in claim 1 wherein said material is
disposed between said rods and said first member.
5. The slip joint defined in claim 1 wherein said material is
disposed between adjacent ones of said rods.
6. The slip joint defined in claim 1 wherein said material is
disposed between said rods and said first member and also between
adjacent ones of said rods.
7. The slip joint defined in claim 1 wherein said material is
formed from a plastic material.
8. The slip joint defined in claim 7 wherein said plastic material
is impregnated with glass or other reinforcing material.
9. The slip joint defined in claim 1 wherein said first member and
said rods are formed from different materials.
10. The slip joint defined in claim 1 wherein said first member is
generally hollow and cylindrical in shape and includes an inner
surface, and wherein said first plurality of grooves is formed in
said inner surface.
11. The slip joint defined in claim 10 wherein said second member
is generally cylindrical in shape and includes an outer surface,
and wherein said second plurality of grooves is formed in said
outer surface.
12. The slip joint defined in claim 1 wherein said first member is
generally cylindrical in shape and includes an outer surface, and
wherein said first plurality of grooves is formed in said outer
surface.
13. The slip joint defined in claim 12 wherein said second member
is generally hollow and cylindrical in shape and includes an inner
surface, and wherein said second plurality of grooves is formed in
said inner surface.
14. The slip joint defined in claim 1 further including a cage for
retaining said balls in said first and second pluralities of
grooves.
Description
BACKGROUND OF THE INVENTION
This invention relates in general to slip joints, such as are
commonly used in vehicle drive train systems, for transmitting
rotational force or torque between telescoping members, while
accommodating a limited amount of relative axial movement
therebetween. In particular, this invention relates to an improved
structure for a splined member that is adapted for use in such a
slip joint.
In a typical land vehicle, a drive train system is provided for
transmitting rotational power from an engine/transmission assembly
to an axle assembly so as to rotatably drive one or more wheels of
the vehicle. A typical drive train system includes a driveshaft
assembly that is connected between an output shaft of the
engine/transmission assembly and an input shaft of the axle
assembly. To accomplish this, a first universal joint is connected
between the output shaft of the engine/transmission assembly and a
first end of the driveshaft assembly, while a second universal
joint is connected between a second end of the driveshaft assembly
and the input shaft of the axle assembly. The universal joints
provide a rotational driving connection from the output shaft of
the engine/transmission assembly through the driveshaft assembly to
the input shaft of the axle assembly, while accommodating a limited
amount of angular misalignment between the rotational axes
thereof.
Not only must the drive train system accommodate a limited amount
of angular misalignment between the engine/transmission assembly
and the axle assembly, but it must also typically accommodate a
limited amount of relative axial movement therebetween. A small
amount of such relative axial movement frequently occurs when the
vehicle is operated. To address this, it is known to provide a slip
joint in the driveshaft assembly of the drive train system. A
typical slip joint includes male and female telescoping members
having respective pluralities of splines formed thereon. The male
splined member has a plurality of outwardly extending splines
formed on the outer surface thereof that cooperate with a plurality
of inwardly extending splines formed on the inner surface of the
female splined member. The cooperating splines of the male and
female members provide a rotational driving connection through the
slip joint, while permitting a limited amount of relative axial
movement therebetween. The slip joint may be provided at the ends
of the driveshaft assembly or in the interior thereof, as
desired.
Conventional splined members are often formed by a machining
process, wherein material is removed from a member to form splines
therein. To accomplish this, the member is initially formed having
a surface of predetermined size and shape. Then, a cutting tool
(such as a hobbing tool) is moved into engagement with the surface
of the member to remove some of the material therefrom. The
material that remains on the member becomes the plurality of
splines. As a result of this machining process, the splines are
usually formed having relatively square faces, i.e., faces that are
generally flat and extend generally radially relative to the
rotational axis of the member. Then, the splined member is coated
with a material having a relatively low coefficient of friction.
The low friction coating is provided to minimize the amount of
force that is required to effect relative movement between the two
splined members. Also, the low friction coating provides a
relatively tight fit between the cooperating splines of the two
splined members, thus minimizing any undesirable looseness
therebetween while continuing to allow free axial movement.
Although the above-described machining process for forming splines
has functioned satisfactorily for many years, it has been found to
be somewhat inefficient. This is because the machining process has
been found to be relatively slow and expensive to perform. Also,
the machining process results in a quantity of scrap material of
which must be disposed. Thus, it would be desirable to provide an
improved structure for a splined member for use in a slip joint and
an improved method for manufacturing the same.
SUMMARY OF THE INVENTION
This invention relates to an improved structure and method for
manufacturing a splined member for use in a slip joint for
transmitting rotational force between two members, while
accommodating a limited amount of relative axial movement
therebetween. The splined member can include a female tubular
member having an inner surface provided with a plurality of
longitudinally extending grooves that are sized and spaced in
accordance with a desired number and position of splines to be
formed. A elongated rod is disposed in each of the longitudinally
extending grooves formed in the inner surface of the female tubular
member. A quantity of positioning material is provided within
spaces provided between the elongated rods and the longitudinally
extending grooves. The positioning material is then hardened to
support the elongated rods in the longitudinally extending grooves
to define a plurality of inwardly extending splines in the female
splined member.
Various objects and advantages of this invention will become
apparent to those skilled in the art from the following detailed
description of the preferred embodiment, when read in light of the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevational view of a vehicle drive
train system including a slip joint in accordance with this
invention.
FIG. 2 is an enlarged, exploded perspective view, partially broken
away, of the slip joint illustrated in FIG. 1.
FIG. 3 is a sectional elevational view of a hollow cylindrical
member that can be used to formed a female splined member for the
slip joint illustrated in FIGS. 1 and 2.
FIG. 4 is a sectional elevational view of the hollow cylindrical
member illustrated in FIG. 3 after having a plurality of
longitudinally extending grooves formed therein.
FIG. 5 is a sectional elevational view of a male positioning
mandrel having a plurality of elongated rods supported thereon.
FIG. 6 is a sectional elevational view showing the male positioning
mandrel and the elongated rods illustrated in FIG. 5 positioned
concentrically within the hollow cylindrical member illustrated in
FIG. 4.
FIG. 7 is a sectional elevational view showing the female splined
member that has been formed after a quantity of positioning
material has been introduced by the male positioning member between
the elongated rods and the longitudinally extending grooves of the
hollow cylindrical member.
FIG. 8 is a sectional elevational view of the assembled slip joint
illustrated in FIGS. 1 and 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, there is illustrated in FIG. 1 a
drive train system, indicated generally at 10, in accordance with
this invention. The illustrated drive train system 10, which is
intended to be representative of any drive train system (vehicular
or otherwise) for transferring rotational power from a source to a
driven device, includes a transmission 12 having an output shaft
(not shown) that is connected to an input shaft (not shown) of an
axle assembly 14 by a driveshaft assembly 15. The transmission 12
and the axle assembly 14 are conventional in the art. The
driveshaft assembly 15 includes a hollow cylindrical driveshaft
tube 16 that extends from a front end adjacent to the transmission
12 to a rear end adjacent to the axle assembly 14. The driveshaft
assembly 15 further includes a pair of universal joints 18 for
rotatably connecting the output shaft of the transmission 12 to the
front end of the driveshaft assembly 15 and for rotatably
connecting the rear end of the driveshaft assembly 15 to the input
shaft of the axle assembly 14. The universal joints 18 are also
conventional in the art.
A slip joint, indicated generally at 20, is provided for connecting
the rear end of the front universal joint 18 to the front end of
the driveshaft tube 16. The structure of the slip joint 20 is
illustrated in detail in FIG. 2. As shown therein, the slip joint
20 includes a female splined member, indicated generally at 22,
including a female tubular member 22a having a plurality of
inwardly extending splines that are defined by a plurality of
circumferentially spaced, elongated rods 23. The elongated rods 23
extend radially inwardly from an inner surface of the female
tubular member 22a to define the splines. The female splined member
22 further has a pair of spaced apart yoke arms (not shown in FIG.
2) formed thereon that extend axially from the female tubular
member 22a and are connected to the front universal joint 18. Thus,
the female splined member 22 is typically referred to as a slip
yoke.
The slip joint 20 also includes a male member, indicated generally
at 24, that includes a cylindrical body portion 24a having a
plurality of circumferentially spaced, longitudinally extending
grooves 24b formed in an outer surface thereof. A plurality of
balls 25 are disposed in the longitudinally extending grooves 24b
formed in the cylindrical body portion 24a. The balls 25 can be
formed from a hardened, low-friction material, such as steel.
Travel of the balls 25 throughout the grooves 24b may be limited by
a mechanical stop or interference member, such as a cage generally
indicated at 19. The male member 24 further includes a reduced
diameter neck portion 24c that is secured to the forward end of the
driveshaft tube 16 in a conventional manner, such as by welding.
The cylindrical body portion 24a and the balls 25 supported thereby
are sized to fit telescopically within the splined end of the
female splined member 22 such that the elongate rods 23 cooperate
with the balls 25 in respective longitudinally extending grooves
24b to form the slip joint 20. The telescoping nature of the slip
joint assembly 20 facilitates the installation of the driveshaft
assembly 15 within a vehicle, accommodates relative axial movement
between the transmission 12 and the axle assembly 14 (such as might
be caused by movement of the vehicle over rough terrain), and
provides for some collapsibility of the driveshaft in the event of
a collision of the vehicle.
Referring back to FIG. 1, a tube yoke 26 is provided for connecting
the rear end of the driveshaft tube 16 to the rear universal joint
18. The tube yoke 26 is conventional in the art and can be secured
to the rearward end of the driveshaft tube 16 in any conventional
manner, such as by welding. It will be appreciated that the female
splined member 22 may alternatively be provided at the forward end
of the driveshaft tube 16 and the pair of spaced apart arms that
are connected to the front universal joint 18 may extend axially
from the male member 24. It will also be appreciated that the slip
joint 20 may alternatively be provided for connecting the rear end
of the driveshaft tube 16 to the rear universal joint 18, and that
the tube yoke 26 may be provided for connecting the front end of
the driveshaft tube 16 to the front universal joint 18.
Alternatively, it will be appreciated that the slip joint 20 may be
provided in an intermediate or interior portion of the driveshaft
tube 16, such as is commonly found in three joint driveshaft
assemblies, wherein the driveshaft tube 16 is split into two
driveshaft tube sections. Similarly, a number of other splined
components are commonly used in conventional driveshaft assemblies,
and the scope of this invention is intended to cover such other
splined components.
Referring now to FIGS. 3 through 7, there is illustrated the steps
in the method of this invention for forming the female splined
member 22 illustrated in FIG. 2. Initially, a hollow cylindrical
member 30, as shown in FIG. 3, is provided. The hollow cylindrical
member 30 may be formed from any desired material, but is
preferably formed from metallic material, such as steel or
aluminum. Then, as shown in FIG. 4, the hollow cylindrical member
30 is re-shaped by any conventional process to form the female
tubular member 22a having an inner surface provided with a
plurality of circumferentially spaced, longitudinally extending
grooves 22b, as shown in FIG. 4. The hollow cylindrical member 30
can be re-shaped in this manner by any conventional process. For
example, the hollow cylindrical member 30 can be re-shaped by
inserting a mandrel (not shown) into the hollow cylindrical member
30 and then collapsing the hollow cylindrical member 30 about the
circumferential surface of the mandrel. The hollow cylindrical
member 30 can, for example, be collapsed in this manner using a
magnetic pulse formation process. The longitudinally extending
grooves 22b are sized and spaced in accordance with a desired
number and position of splines to be formed on the inner surface of
the female tubular member 22a.
Next, as shown in FIG. 5, a male positioning mandrel, indicated
generally at 40, is provided. The male positioning mandrel 40
includes an outer surface having a plurality of circumferentially
spaced, longitudinally extending grooves 40a provided in the outer
surface thereof. Similar to the grooves 22b discussed above, the
grooves 40a are also sized and circumferentially spaced in
accordance with a desired number and position of splines to be
formed on the inner surface of the female tubular member 22a. Next,
an elongated rod 23 is disposed in each of the longitudinally
extending grooves 40a formed in the outer surface of the male
positioning mandrel 40. The elongated rods 23 can be formed from
any desired material, but preferably are formed from a strong,
rigid material, such as steel, to provide a hardened wear surface.
The elongated rods 23 can be temporarily retained in the
longitudinally extending grooves 40a by any conventional means. For
example, the elongated rods 23 can be temporarily retained in the
grooves 40a by a mechanical retainer, such as a cage (not shown),
adhesives, and the like. Alternatively, the elongated rods 23 can
be temporarily retained in the grooves 40a sizing such grooves 40a
to frictionally engage and retain the elongated rods 23
therein.
The male positioning mandrel 40 can further include a mechanism for
injecting a quantity of a positioning material about the elongated
rods 23. The injecting mechanism can, for example, include a
manifold, indicated generally at 40b, that is provided in the
interior of the male positioning mandrel 40. The illustrated
manifold 40b is an enlarged central bore that is formed through the
interior of the male positioning mandrel 40. The injecting
mechanism can further include a plurality of passageways 40c that
extend radially outwardly from the manifold 40b to the outer
surface of the male positioning mandrel 40. In the illustrated
embodiment, the passageways 40c are axially and circumferentially
spaced apart from one another and extend radially outwardly between
adjacent ones of the longitudinally extending grooves 40a provided
in the outer surface of the male positioning mandrel 40. However,
the passageways 40c may be oriented in any desired configuration.
Lastly, the injecting mechanism can include one or more channels
40d formed in the male positioning mandrel 40 through which coolant
can flow. The purposes for the manifold 40b, the passageways 40c,
and the coolant channels 40d will be explained below.
As shown in FIG. 6, the male positioning mandrel 40 having the
elongated rods 23 supported thereon can be inserted concentrically
within the female tubular member 22a. When so positioned, the
radially outermost portions of the elongated rods 23 extend within
the adjacent longitudinally extending grooves 22b formed in the
female tubular member 22a. The male positioning mandrel 40 supports
the elongated rods 23 in this orientation while a quantity of
positioning material 50 is introduced between the outer surface of
the male positioning mandrel 40 and the inner surface of the female
tubular member 22a. The positioning material 50 can, for example,
be embodied as a hardenable liquid material that is introduced
through the injecting mechanism described above. To accomplish
this, the positioning material 50 is injected into the manifold 40b
and radially outwardly through the passageways 40c. Alternatively,
the positioning material 50 can be injected through the female
tubular member 22a through ports (not shown) provided through the
female tubular member 22a or in any other manner.
When injected, the positioning material 50 fills the spaces between
the elongate rods 23 and the longitudinally extending grooves 22b
in the female tubular member 22a. The positioning material 50 can
also be injected into the annular spaces between the outer surface
of the male positioning mandrel 40 and the inner surface of the
female tubular member 22a, between adjacent ones of the elongated
rods 23. The positioning material 50 can be embodied as any
material that is suitable for retaining the elongated rods 23 in
the longitudinally extending grooves 22b provided in the inner
surface of the female tubular member 22. For example, the
positioning material 50 can be a molten plastic material that is
filled or impregnated with glass or other reinforcing material. The
positioning material 50 can, if desired, be heated to facilitate
flow thereof through the manifold 40b and the passageways 40c.
Once the positioning material 50 has been injected, it is caused to
retain the elongated rods 23 in the longitudinally extending
grooves 22b provided in the inner surface of the female tubular
member 22. This can be accomplished by causing the positioning
material 50 to change from a liquid state to a solid state. This
change of state can be achieved by allowing the hot liquid
positioning material 50 to cool and thereby solidify. Such cooling
can be expedited by the passage of coolant through the coolant
channels 40d formed in the male positioning mandrel 40. In the
illustrated embodiment, the passageways 40c are sized to be
relatively small in comparison with the manifold 40b. This is
desirable because it facilitates the separation of the positioning
material 50 injected about the elongated rods 23 from the
positioning material that remains in the passageways 40c, thereby
allowing easy removal of the male positioning mandrel 40 from the
female tubular member 22b after the injection process is
completed.
Upon hardening, the positioning material 50 retains the elongates
rods 23 in the longitudinally extending grooves 22b provided in the
inner surface of the female tubular member 22a. After the
positioning material 50 has hardened, the male positioning mandrel
40 is removed, as shown in FIG. 7. The elongate rods 23 remain in
the longitudinally extending grooves 22b in the female tubular
member 22a, thereby forming a plurality of internal splines. Thus,
the longitudinally extending grooves 22b need not be precisely
formed to conform closely to the elongated rods 23, but rather need
only be generally formed to allow the positioning material 50 to
envelop the elongated rods 23 and support them on the female
tubular member 22a. Thus, the positioning material 50 functions to
both position the elongated rods 23 and retain them in desired
positions on the female tubular member 22a. The positioning
material 50 can also function to physically insulate the elongated
rods 23 from the female tubular member 22a. Consequently, the
female tubular member 22 and the elongate rods 23 can be formed
from dissimilar materials without being susceptible to undesirable
galvanic corrosion. For example, the female tubular member 22 can
be formed from a relatively lightweight material, such as aluminum,
while the elongated rods 23 can be formed from a relatively heavier
material, such as steel. The positioning material 50 provides a
barrier between the aluminum and steel to prevent the occurrence of
galvanic corrosion.
After the female splined member 22 has been manufactured in
accordance with the method of this invention, the slip joint 20 is
assembled as shown in FIG. 8. In this assembled condition, the
balls 25 are supported in the elongated grooves 24b in the
cylindrical body portion 24a of the male member 24 of the slip
joint 20. The cage 19 is provided about the cylindrical body
portion 24a. The cage 19 functions to retain the balls 25 in a
fixed relation to one another and limit the travel of the balls 25
in the elongated grooves 24b in the male member 24. The male member
24 and the balls 25 and cage 19 supported by the male member 24 are
inserted into the female splined member 22 so that the balls 25 in
each of the elongated grooves 24b in the male member 24 are
disposed between two adjacent elongate rods 23. The balls 25 engage
or cooperate with the elongate rods 23 in a circumferential
direction (in a clockwise or counter-clockwise direction when
viewing FIG. 8) to transmit torque or rotational force between the
female splined member 22 and the male member 24. Moreover, the
female splined member 22 and the male member 24 are telescopically
displaceable relative to one another. The balls 25 facilitate
unencumbered telescopic displacement between the female splined
member 22 and the male member 24. As stated above, the telescoping
nature of the slip joint assembly 20 facilitates the installation
of the driveshaft assembly 15 within a vehicle, accommodates
relative axial movement between the transmission 12 and the axle
assembly 14, and provides for some collapsibility of the driveshaft
in the event of a collision of the vehicle.
Although this invention has been described in the context of the
illustrated female splined member 22, it will be appreciated that
the same general method can be used to form the male splined member
24, wherein the elongated rods 23 are supported in grooves formed
in the outer surface of the body portion 24a of the male splined
member by the positioning material 50.
In accordance with the provisions of the patent statutes, the
principle and mode of operation of this invention have been
explained and illustrated in its preferred embodiment. However, it
must be understood that this invention may be practiced otherwise
than as specifically explained and illustrated without departing
from its spirit or scope.
* * * * *